The Natural Wastewater Plant Treatment is a NBS based on the concept of the Waterharmonica in its desigh. This NBS is included a urban park to provide sustainable water for irrigation with vertical SSFW (SSFW) working in parallel and followed by a SFW (Surface Flow Wetlands), which will constitute a network with a positive effect on functionality. A very simple calculati on. An inhabita nt of Valladolid produces around 300 L per day of wastewater. Irrigation needs of an urban green surface in Valladolid are around 4.5L/ m2. This implies that, suitably treated, with the wastewater of every citizen could irrigate 67 m2 of green areas. This NBS is a very sustainable solution to reduce dramatically drinking water consumption for irrigation.